Fig 5 - uploaded by Yashar Akrami
Content may be subject to copyright.
Component-separated CMB maps at 80 resolution. Columns show Stokes I, Q, and U, respectively, while rows show results derived with different component-separation methods. The Galactic plane region in the SMICA maps results from a pre-processing step (masking and diffusive inpainting of a narrow Galactic region in all frequency channels), while no masks are applied to the other maps. In this plot, monopoles and dipoles have been subtracted with parameters fitted outside a |b| < 30 • mask.
Source publication
We present full-sky maps of the cosmic microwave background (CMB) and polarized synchrotron and thermal dust emission, derived from the third set of Planck frequency maps. These products have significantly lower contamination from instrumental systematic effects than previous versions. The methodologies used to derive these maps follow closely thos...
Contexts in source publication
Context 1
... adopts its own relative calibration between frequency channels. In 2015, this process was applied to frequency channels from 44 to 353 GHz; however, since then we have found that the uncertainty in the 44 GHz channel was larger than expected, and that the previously reported value was inaccurate (see Fig. D.5). In the new release, we adopt a more conservative approach, and limit re-calibration to 70, 100, and 217 GHz, taking the 143 GHz channel as a reference; see Appendix D.1 for further ...
Context 2
... a detailed analysis of the higher-order statistical properties of these maps, see Planck Collaboration VII (2020). Figure 5 shows the final full-mission Planck 2018 CMB component-separated maps derived by each of the four pipelines 9 , both in intensity (left column) and polarization (middle and right The Galactic plane region in the SMICA maps results from a pre-processing step (masking and diffusive inpainting of a narrow Galactic region in all frequency channels), while no masks are applied to the other maps. In this plot, monopoles and dipoles have been subtracted with parameters fitted outside a |b| < 30 • mask. ...
Context 3
... adopts its own relative calibration between frequency channels. In 2015, this process was applied to frequency channels from 44 to 353 GHz; however, since then we have found that the uncertainty in the 44 GHz channel was larger than expected, and that the previously reported value was inaccurate (see Fig. D.5). In the new release, we adopt a more conservative approach, and limit re-calibration to 70, 100, and 217 GHz, taking the 143 GHz channel as a reference; see Appendix D.1 for further ...
Context 4
... a detailed analysis of the higher-order statistical properties of these maps, see Planck Collaboration VII (2020). Figure 5 shows the final full-mission Planck 2018 CMB component-separated maps derived by each of the four pipelines 9 , both in intensity (left column) and polarization (middle and right The Galactic plane region in the SMICA maps results from a pre-processing step (masking and diffusive inpainting of a narrow Galactic region in all frequency channels), while no masks are applied to the other maps. In this plot, monopoles and dipoles have been subtracted with parameters fitted outside a |b| < 30 • mask. ...
Citations
... These telescopes are specifically designed to reach key science targets including constraints of the tensor-to-scalar ratio r, the effective number of relativistic species N ef f , the sum of neutrino masses Σm ν , deviations from the cosmological constant, galaxy evolution feedback efficiency, and the epoch of reionization [1]. Galactic and extra-Galactic foreground-subtracted CMB data are critical to achieving these science goals [1][2][3][4][5][6][7][8][9]. To achieve sensitivities that enable this science, SO will be observing across six spectral bands from 27 to 285 GHz. ...
... Focal planes across the telescopes will be dichroic, observing at the Low-Frequency (LF) bands centered at 27 and 39 GHz, the Mid-Frequency (MF) primary CMB bands centered at 93 and 145 GHz, and the Ultra-High-Frequency (UHF) bands centered at 225 and 285 GHz. The UHF bands will characterize thermal dust emission and the LF bands will characterize synchrotron emission, which are the dominant emission sources in Galactic polarization signals [9][10][11]. Here, we focus on the LF focal plane development studying primarily Galactic synchrotron emission. ...
The Simons Observatory (SO) is a cosmic microwave background (CMB) experiment located in the Atacama Desert in Chile that will make precise temperature and polarization measurements over six spectral bands ranging from 27 to 285 GHz. Three small aperture telescopes (SATs) and one large aperture telescope (LAT) will house 60,000 detectors and cover angular scales between one arcminute and tens of degrees. We present the performance of the dichroic, low-frequency (LF) lenslet-coupled sinuous antenna transition-edge sensor (TES) bolometer arrays with bands centered at 27 and 39 GHz. The LF focal plane will primarily characterize Galactic synchrotron emission as a critical part of foreground subtraction from CMB data. We will discuss the design, optimization, and current testing status of these pixels.
... As expected, extragalactic components can be strongly biased, while diffuse Galactic foregrounds mainly dominant at large scales [49,50] are less affected by main beam chromaticity. By construction, in our formalism the CMB power spectrum should remain unaffected by beam chromaticity, assuming that the "CMB" beam is correctly estimated. ...
We investigate the impact of beam chromaticity, i.e., the frequency dependence of the beam window function, on cosmological and astrophysical parameter constraints from CMB power spectrum observations. We show that for future high-resolution CMB measurements it is necessary to include a color-corrected beam for each sky component with a distinct spectral energy distribution. We introduce a formalism able to easily implement the beam chromaticity in CMB power spectrum likelihood analyses and run a case study using a Simons Observatory (SO) Large Aperture Telescope-like experimental setup and within the public SO software stack. To quantify the impact, we assume that beam chromaticity is present in simulated spectra but omitted in the likelihood analysis. We find that, for passbands of fractional width , neglecting this effect leads to significant biases, with astrophysical foreground parameters shifting by more than and cosmological parameters by significant fractions of the error.
... In fact, CMB studies have long benefited from alternative representations of the usual harmonic analysis, as exemplified by the extensive use of wavelets [12][13][14][15][16][17], Minkowski functionals [18][19][20][21], and multipole vectors [22][23][24][25][26]. These are versatile tools, applicable to a wide range of topics in CMB data analysis, from component separation methods [27], to non-Gaussianities [16,19,20], and cosmic topologies [24,28]. Alternatively, if a null test of the GSI hypotheses is desired, then one can keep the usual harmonic approach and dispose of anisotropic and modelindependent implementations of two-point correlation functions and their estimators [29][30][31][32][33][34]. ...
... Modes in the range 2 ≤ ℓ ≤ 1500 were already investigated in [26] using a simplified statistical and numerical pipeline. Although the noise power spectrum only surpasses the CMB one for ℓ > 1700 for all four maps [27], the noise is already relevant at lower multipoles, especially for individual a ℓm s. Indeed, in [26], a strong deviation of the GSI framework was detected at ℓ ≳ 1300, hinting at the presence of anisotropic noise and or residual foreground in the maps. ...
... Regarding the underlying models to which the data are compared, we consider four separate cases: full-sky maps, masked maps, full-sky maps with noise, and masked maps with noise. Masked results, when quoted, were produced using the Planck Common Mask [27]. ...
Cosmological data collected on a sphere, such as CMB anisotropies, are typically represented by the spherical harmonic coefficients, denoted as . The angular power spectrum, or , serves as the fundamental estimator of the variance in this data. Alternatively, spherical data and their variance can also be characterized using Multipole Vectors (MVs) and the Fr\'echet variance. The vectors that minimize this variance, known as Fr\'echet Vectors (FVs), define the center of mass of points on a compact space, making them highly sensitive to small displacements of these points. This sensitivity makes FVs excellent indicators of statistical correlations between different multipoles. We demonstrate this using both simulations and real data. Through simulations, we show that FVs enable a blind detection and reconstruction of the location associated with a mock Cold Spot anomaly introduced in an otherwise isotropic sky. Applying this to the 2018 Planck maps, we implement several improvements on previous model-independent tests of Gaussianity and statistical isotropy, down to arc-minute scales. When compared with simulated maps that incorporate masking and anisotropic noise, for , while Planck's MVs appear consistent with these hypotheses, the corresponding FVs reject them with significances between 5.2 and , depending on the component separation method.
... These two emission mechanisms are obviously prominent around the Galactic plane, but are also clearly detectable at higher latitudes [33]. In the context of the Planck mission, various foreground cleaning procedures have been employed [34]. Among them, we mention two categories: (i) parametric-fitting [35][36][37][38][39][40], which recovers the CMB signal by marginalising over the spectral parameters of Galactic foregrounds; and (ii) the so-called 'blind' methods [41][42][43][44][45][46], whose purpose is to recover a cleaned CMB blackbody signal, without any assumption on the spectral energy distribution (SED) of foreground emission. ...
... In this work, as anticipated in section 1, we adopt the NILC pipeline to recover CMB B modes from LiteBIRD multifrequency simulated data. Such a method has already been largely employed in CMB data analysis, e.g. for WMAP [51] and Planck [34], and it will also be one of the foreground cleaning pipelines for other next-generation CMB experiments, such as Simons Observatory [67]. NILC falls in the category of blind component-separation methods, since it performs a reconstruction of the CMB signal without any assumptions on the foreground spectral properties. ...
... In the d1s1 model, the dust and synchrotron spectral indices vary across the sky. The dust template corresponds to the 353-GHz map from Planck [5,31] and the dust spectral parameters maps are obtained by applying the Commander pipeline [34] to the Planck data set. The synchrotron template corresponds to the WMAP 9-year 23-GHz Q/U maps [3] and the spectral index map is obtained by combining the Haslam 408-MHz data and WMAP 23-GHz 7-year data [61]. ...
Future cosmic microwave background (CMB) experiments are primarily targeting a detection of the primordial B-mode polarisation. The faintness of this signal requires exquisite control of systematic effects which may bias the measurements. In this work, we derive requirements on the relative calibration accuracy of the overall polarisation gain () for LiteBIRD experiment, through the application of the blind Needlet Internal Linear Combination (NILC) foreground-cleaning method. We find that minimum variance techniques, as NILC, are less affected by gain calibration uncertainties than a parametric approach, which requires a proper modelling of these instrumental effects. The tightest constraints are obtained for frequency channels where the CMB signal is relatively brighter (166 GHz channel, ), while, with a parametric approach, the strictest requirements were on foreground-dominated channels. We then propagate gain calibration uncertainties, corresponding to the derived requirements, into all frequency channels simultaneously. We find that the overall impact on the estimated r is lower than the required budget for LiteBIRD by almost a factor 5. The adopted procedure to derive requirements assumes a simple Galactic model. We therefore assess the robustness of obtained results against more realistic scenarios by injecting the gain calibration uncertainties, according to the requirements, into LiteBIRD simulated maps and assuming intermediate- and high-complexity sky models. In this case, we employ the so-called Multi-Clustering NILC (MC-NILC) foreground-cleaning pipeline and obtain that the impact of gain calibration uncertainties on r is lower than the LiteBIRD gain systematics budget for the intermediate-complexity sky model. For the high-complexity case, instead, it would be necessary to tighten the requirements by a factor 1.8.
... Due to the joint analysis, there are lower levels of noise and systematic in both frequency and component maps at essentially all angular scales. To mask foreground residuals around the Galactic plane as well as bright extragalactic point sources, we apply the Planck common mask based on the union of the uncertainties of four different foreground subtraction methods used in the Planck Public Release 3 (Planck PR3) [23] analysis [24] and leaves about 78% of the sky area suitable for statistical studies. ...
... 1. We first measure the pseudo angular power spectrum pseudo − C ℓ s of each masked map. In order to avoid a possible noise bias, we use the cross-spectrum between detector sets A and B of the PR4 maps cleaned with the SEVEM component separation method (see [24] for details). ...
We perform cosmological parameters estimation on Planck Cosmic Microwave Background (CMB) maps masking the recently discovered foreground related to nearby spiral galaxies. In addition, we also analyse the association between these foreground regions and recent claims of cosmological causal horizons in localized CMB parameter estimates. Our analysis shows consistent cosmological parameter values regardless of the masking approach, though reduced sky areas introduce larger uncertainties. By modelling the new extragalactic foreground, we identify a resemblance with local parameter variation maps with a statistical significance at the 3 sigma level, suggesting that a simplified foreground model partially accounts, (40-50)% correlation with 15% uncertainty, for the observed causal horizons. These findings add new evidence to the existence of the new foreground associated with large spiral galaxies and show that estimates of cosmological parameters on smaller patches on the sky can be largely affected by these foregrounds, but that the parameters taken over the full sky are unaltered.
... We implement the models considered in the CAMB code and use their output to perform a statistical analysis by the Monte Carlo Markov Chain (MCMC) approach, through the cobaya code [53,54], in which the necessary likelihoods and data sets are implemented. In particular, we take the recent TTTEEE HiLLiPoP high-ℓ likelihood [55], 3 together with the low-multipole Commander for TT modes [56,57] and the LoLLiPoP one for EE modes. 4 Furthermore, we combine this with the PR4 likelihood for the CMB lensing potential [58]. ...
In the warm inflation scenario, the early cosmic acceleration is driven by the inflaton coupled to thermal fields, decaying into radiation and leaving a hot universe populated by relativistic particles after the end of inflation. The interaction is usually modeled by a dissipation coefficient Υ that contains the microphysics of the model. In this work, we adopt a well-motivated potential V(ϕ)=λ/4ϕ ⁴ and constrain a variety of Υ parameterizations by using updated Cosmic Microwave Background data from the Planck and BICEP/Keck Array collaborations. We also use a Bayesian statistical criterion to compare the observational viability of these models. Our results show a significant improvement in the constraints over past results reported in the literature and also that some of these warm inflation models can be competitive compared to Starobinsky inflation.
... The impressive results of WMAP [1,2] and Planck [3][4][5] experiments have significantly expanded our knowledge of fundamental physical processes in the early Universe and brought us closer to a high-precision estimation of the main cosmological parameters. ...
We present a detailed test for Gaussianity of Planck polarization data using statistics of unpolarized points on the sky, i.e. such points where the linear polarization vanishes. The algorithm we propose for finding such points is stable and guarantees their 100% detection. Our approach allows us to analyze the data for Gaussianity of the signal at different angular scales and detect areas on the polarization maps with a significant contribution from unremoved non-Gaussian foregrounds. We found very strong deviations from Gaussianity for E and B modes in the observational data both over the entire sky and in some specific regions of the celestial sphere.
... We do not involve the point sources in our main analysis because they are masked by the point source mask and the remnant effects are weak. In our foreground model, the thermal dust polarization maps are generated from the GNILC template of the Planck 2018 release [45], scaled to different frequencies by a modified blackbody SED with the spatially-varying dust temperature and spectral indices from the GNILC Planck 2015 dust maps best-fit at 5 ′ resolution [46]. The synchrotron polarization template is based on the Planck 2018 SMICA map, and it is scaled by a power law SED with a fixed β s of -3.08. ...
... The needlet ILC (NILC) has been used to extract CMB anisotropies for numerous CMB experiments since WMAP [38,45,[58][59][60][61][62][63][64][65][66]. In NILC, each frequency map is filtered by a set of needlet bands in harmonic domain, and the ILC procedure is implemented independently on each pixel for each filtered map. ...
The correlations between T, E modes and B modes in cosmic microwave background (CMB) radiation, which are expected to vanish under parity symmetry, have become a sensitive probe of the new physics beyond the standard model. In this paper, we forecast the estimation of TB and EB cross power spectra using NILC and cILC on AliCPT-1 simulations together with Planck HFI and WMAP K maps as ancillary data. We find that, NILC performs better than cILC on measuring TB and EB correlations in light of its lower uncertainties. In terms of the birefringence angle estimation without assuming systematic errors, the combination of CMB TB and EB spectra from NILC cleaned simulations could reach a sensitivity of |β| < 0.058∘ with 2σ significance for the first observing season of AliCPT. Tripling the survey duration will improve this sensitivity to |β| < 0.041∘.
... These are astrophysical emissions between the last scattering surface and us. Precisely, the CMB has been measured in several frequency channels to exploit their different frequency response and to allow component-separation algorithms [3][4][5][6][7] to subtract an important part of them. Unfortunately, strongly contaminated regions such as the Galactic plane and the locations of extragalactic point sources can not be used for the statistical analyses, even after applying component-separation methods. ...
... Once the matrix is computed and rotated, we reorder the columns and rows in a way that all the unmasked pixels are in the first entries and the masked ones in the last entries. 3 Then, the Cholesky decomposition allows one to sample from the desired distribution by solving the following system, ...
... Thus in equation A8, the negative sign corresponds to the case where the z component of the vectorrij, the vector of the great circle connecting the two pixels, is positive, and vice versa. 3 In the case of a full T QU covariance matrix, the order considered is: unmasked T pixels, unmasked Q pixels, unmasked U pixels, masked T pixels, masked Q pixels and masked U pixels. ...
The presence of astrophysical emissions in microwave observations forces us to perform component separation to extract the Cosmic Microwave Background (CMB) signal. However, even in the most optimistic cases, there are still strongly contaminated regions, such as the Galactic plane or those with emission from extragalactic point sources, which require the use of a mask. Since many CMB analyses, especially the ones working in harmonic space, need the whole sky map, it is crucial to develop a reliable inpainting algorithm that replaces the values of the excluded pixels by others statistically compatible with the rest of the sky. This is especially important when working with Q and U sky maps in order to obtain E- and B-mode maps which are free from E-to-B leakage. In this work we study a method based on Gaussian Constrained Realizations (GCR), that can deal with both intensity and polarization. Several tests have been performed to asses the validation of the method, including the study of the one-dimensional probability distribution function (1-PDF), E- and B-mode map reconstruction, and power spectra estimation. We have considered two scenarios for the input simulation: one case with only CMB signal and a second one including also Planck PR4 semi-realistic noise. Even if we are limited to low resolution maps, Nside = 64 if T, Q and U are considered, we believe that this is a useful approach to be applied to future missions such as LiteBIRD, where the target are the largest scales.
... The origin of the BAU remains a mystery, but it is clear that the observed yield of the baryon asymmetry, Y obs B ≈ 8.7 × 10 −10 [106], should have existed before the onset of Big Bang Nucleosynthesis at T BBN ≈ 1 MeV. Leptogenesis [107], which is based on the type-I seesaw mechanism [108][109][110][111], explains the observed BAU by generating a net leptonic asymmetry, ∆L, through the out-of-equilibrium dynamics of at least two gauge singlet fermions, also known as Right Handed Neutrinos (RHNs), N i where i is a generational index. ...
When light primordial black holes (PBHs) evaporate in the early Universe, they locally reheat the surrounding plasma, creating hot spots with temperatures that can be significantly higher than the average plasma temperature. In this work, we provide a general framework for calculating the probability that a particle interacting with the Standard Model can escape the hot spot. More specifically, we consider how these hot spots influence the generation of the baryon asymmetry of the Universe (BAU) in leptogenesis scenarios, as well as the production of dark matter (DM). For leptogenesis, we find that PBH-produced right-handed neutrinos can contribute to the BAU even if the temperature of the Universe is below the electroweak phase transition temperature, since sphaleron processes may still be active within the hot spot. For DM, particles emitted by PBHs may thermalise with the heated plasma within the hot spot, effectively preventing them from contributing to the observed relic abundance. Our work highlights the importance of including hot spots in the interplay of PBHs and early Universe observables
